1. Field of the Invention
The present invention relates to a gas rate sensor system which is capable of detecting an angular velocity which has an effect on the gas rate sensor body.
2. Description of the Prior Art
In general, a gas rate sensor provides an output signal in response to any difference between the output signals supplied from a pair of thermal sensing elements, which difference appears when the gas flow ejected from a gas nozzle deviates to flow more on one of the thermal sensing elements than on the other due to the influence on the gas flow by an applied motion whose angular velocity is to be determined in terms of its speed and direction.
The angular velocity is determined by detecting a small inbalance in the heat dissipation from the pair of thermal sensing elements due to the deviation of the gas flow, and therefore the surrounding temperature change has a great effect on the sensitivity of the gas rate sensor, particularly an adverse effect of lowering the sensitivity of the gas rate sensor. This necessitates the use of temperature compensating means in the gas rate sensor.
In an attempt to reduce the adverse effect caused by the surrounding temperature the gas rate sensor is subjected to forced heating by using appropriate heaters, and the temperature within the gas rate sensor is detected by appropriate temperature sensors, and the temperature within the gas rate sensor is controlled so as to remain constant.
Disadvantageously, the sensitivity of the gas rate sensor and the offset value remain too unstable to provide correct output signal until the temperature within the gas rate sensor has reached a stable condition after connecting the electric heater to an associated power supply. Also, such forced heating makes it practically difficult to control the temperature within the gas rate sensor to the extent that it is assured that the gas rate sensor can provide a correct output signal.
With the above in mind one object of the present invention is to provide a gas rate sensor system which is capable of correcting the gas rate sensor output signal in a most appropriate way to meet the instantaneous temperature change within the gas rate sensor, allowing the temperature within the gas rate sensor to vary.
To attain this object a gas rate sensor which provides an output signal in response to any difference between the output signals supplied from a pair of thermal sensing elements, which difference is caused when the gas flow ejected from a gas nozzle deviates to flow more on one of the thermal sensing elements than on the other due to the influence of an anuglar velocity to be determined on the gas flow, is improved according to the present invention in that said gas rate sensor is equipped with: means to detect the temperature within the gas rate sensor; and means to carry out an arithmetic operation for correction of gas rate sensor output signals by selectively using present values representing changes of the gas rate sensor output signal with temperature.